Section II TROUBLESHOOTING - TM-11-5820-401-34-30398

TM 11-5820-401-34-3/0967-LP-432-3060

Section II TROUBLESHOOTING

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General. . . . . . . . . . . . . . . . . . .. . . . . . . . . . . .......................

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Gross Troubleshooting Preliminary lnstructions . . . . . . . . .. . . . . .. . . . . . . . . . ..

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No Audio Troubleshooting.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SINAD Test Failure Troubleshooting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..

Squelch Test Failure Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Audio Distortion Test Failure Troubleshooting. . . . . . . . . .. . . . . . . . . . . . . . . . .. . . . . . . . . . . .

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Audio Response Test Failure (Normal Mode)

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Troubleshooting . . . . . . . . . . . . ........... . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . .

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SelectivityTest Failure Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

A1000 Assembly Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

A2000, A3000Assemblies Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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A4000 Assembly Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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A5000 Assembly Troubleshoot in. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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GENERAL.

This section contains troubleshooting charts which will help you diagnose failures in the receiver

R-442/VRC. The troubleshooting charts are designed to isolate faults in response to specific

performance problems noted during performance testing in section l of this chapter.

There are two basic kinds of troubleshooting charts provided: gross failure troubleshooting and

performance degradation troubleshooting. Both kinds of troubleshooting in this section are based on

the use of Tes tCable No. 1 and TMDE.

GROSS FAILURE TROUBLESHOOTING

Gross failure troubleshooting is generated by failure of the VOLUME control test, the first of the per-

formance tests in section l. Failure of the VOLUME control test indicates that no audio at all is available

at the receiver's Ioudspeaker jack. This implies a total failure of some module or component resulting

in complete loss of signal, Therefore, the gross troubleshooting charts are designed to help you

locate the failed module or componen~ with the assumption that the failed part does not operate at all.

This assumption differs from the approach taken in performance degradation troubleshooting, which

assumes that a module or component may be responsible for slight defect symptoms because the part

may be only partialIy operational.

PERFORMANCE DEGRADATION TROUBLESHOOTING

When the receiver produces audio output, but the signal fails to meet certain standards, the receiver's

performance is considered degraded. Degraded performance can result in weak audio, limited

reception range, distortion, and many other problems.

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